We -- as Christians -- are supposed to be good all the time as a way to be true ambassadors of God on earth and beyond our limited human capacity of understanding. The best practice to achieve this (or so I've been told numerous times) is to pray, talk to God, ask for favors, be true servants of God and do everything on God's behalf. As someone told me, you should start the day with a prayer, live that prayer through out the day and end the day with a prayer.
"There are many who recommend opening the day with a prayer, and then continuing to live that prayer. Or, put another way, to do what we do -- even, say, washing the dishes, riding the subway -- in a meditative sort of gift to God... Then closing each day with even a simple word of gratitude."
http://project05952381.blogspot.com/2010/10/then-how-much-more-response.html
Of course, this is something that many Christians fail to do or care not to do at times (myself included in the second group too many times). Said all this, if we dare to call ourselves CHRISTIANS, we've got a higher obligation to be good as we do good in God's name.